Thomson-Csf

Thomson Consumer Electronics Inc.

Thomson Multimedia S.a.

Francedillaois Maurice

Michel Sonrier

Joseph Colineau

Jean-Marc Coutellier

Charaf Hanna

Francedillaois-Xavier Pirot

A magneto-optic multitrack reading head which features a structure with plane layers deposited in a course of a same deposition procedure. These layers include a magnetic layer exhibiting a Kerr effect, an inter-iron gap layer and a magnetic layer for magnetic circuit closing. The magnetic layers define adjacent elementary heads, so as to be able to read multitrack media.

Magneto-optic multitrack reading head with a kerr effect layer

A method and system of magnetic recording of information elements on several parallel tracks whereby the recording of information elements on a track is accomplished by inducing a magnetic field having a predetermined direction in a zone on the track and, during this recording, inducing a magnetic field with a reverse direction in zones of the neighboring tracks. A winding (L0, L1, L2) of each head is coupled to at least two winding of neighboring heads. A control current transmitted to the head provides at least one current diverted towards the neighboring heads.

Method and system for the magnetic recording of information elements and

System for recording/writing on a recording medium in which there are distributed, on the tracks, groups (G0) of tracks with positive continuous components and groups (G1) of tracks with negative continuous components. In reading, the values of the different signals are integrated for each track. Then, on the one hand, a first addition circuit S1 adds up the results of integration of the first tracks of each group of tracks and, secondly, a second addition circuit S2 adds up the results of integration of the last tracks of each group of tracks. A comparison circuit (CD) compares the results of additions of the two addition circuits to correct the track-following operation.

Information recording medium encoded to enable track following and

A method for the making of a magnetic recording/reading head comprises the following steps:

Method of making a magnetic recording/reading head

Magnetic write/read heads for writing/reading information on a recording medium passing in front of the heads include several groups of magnetic write/read heads, each group of magnetic write/read heads including several pairs of poles. Each pair of poles is separated by a head gap of an integer multiple of an elementary track width b and forms several head gaps E0 to E7. The head gaps (for example El) have a first width such that they can write across a first width of the recording medium, and the second head gaps (for example E2) have a second width less than the first width and are arranged in such a way that the second head gaps write/read an area of the recording medium superimposed on the area of the recording medium write/read by the first head gaps. The magnetic write/read heads are suitable for applications where multitrack write/read heads are required.

Multitrack magnetic write/read head arrangement with integal multiple

A magneto-optic multitrack reading head on which incident light impinges. The magneto-optic head includes a first layer of magnetic material exhibiting a Kerr effect and which partially reflects the incident light to generate a first reflection ray and which partially transmits the incident light to generate an internal ray. The magneto-optic head further includes a second layer of magnetic material and a layer of non-magnetic material, the non-magnetic layer having a thickness of one-half of a wavelength of the incident light and formed between the first and second layers of magnetic material and through which the internal ray passes. The internal ray is further reflected after passing through the layer of non-magnetic material to generate a second reflection ray parallel to and in-phase with the first reflection ray. The above structure improves the merit factor and signal-to-noise ratio of the magneto-optic reading head.

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Verrieres le Buisson, France

Francedillaois Maurice